Background: Obesity is a well-established risk factor for atrial fibrillation (AF). Whether body fat depots differentially associate with AF development remains unknown.
Methods: In the prospective population-based Rotterdam Study, body composition was assessed using dual-energy X-ray absorptiometry (DXA) and liver and epicardial fat using computed tomography (CT). A body composition score was constructed by adding tertile scores of each fat depot. Principal component analysis was conducted to identify potential body fat distribution patterns. Cox proportional hazards regression was used to calculate hazard ratios and 95% confidence intervals (HR; 95% CI) per 1-standard deviation increase in corresponding fat depots to enable comparisons.
Results: Over a median follow-up of 9.6 and 8.6 years, 395 (11.4%) and 172 (8.0%) AF cases were ascertained in the DXA and the CT analyses, respectively. After adjustments for cardiovascular risk factors, absolute fat mass (HR; 95% CI 1.33; 1.05-1.68), gynoid fat mass (HR; 95% CI 1.36; 1.12-1.65), epicardial fat mass (HR; 95% CI 1.27; 1.09-1.48), and android-to-gynoid fat ratio (HR; 95% CI 0.81; 0.70-0.94) were independently associated with new-onset AF. After further adjustment for lean mass, associations between fat mass (HR; 95% CI 1.17; 1.04-1.32), gynoid fat mass (HR; 95% CI 1.21; 1.08-1.37), and android-to-gynoid fat ratio (HR; 95% CI 0.84; 0.72-0.97) remained statistically significant. Larger body fat score was associated with a higher AF risk (HR; 95% CI 1.10; 1.02-1.20). Borderline significant association was found between a subcutaneous fat predominant pattern with AF onset (HR; 95% CI 1.21; 0.98-1.49).
Conclusions: Various body fat depots were associated with new-onset AF. Total fat mass and gynoid fat mass were independently associated with AF after adjustment for body size. The inverse association between android-to-gynoid fat ratio with AF presents a novel finding. A significant dose-response relationship between body fat accumulation and AF was observed. Our results underscore the predominant role of subcutaneous fat on AF development among a middle-aged and elderly population.
The Rotterdam Study is supported by Erasmus Medical Center and
Erasmus University, Rotterdam; the Netherlands Organization for Scientific
Research (NWO); the Netherlands Organization for Health Research and
Development (ZonMw); the Research Institute for Diseases in the Elderly
(RIDE); the Netherlands Genomics Initiative; the Ministry of Education, Culture and Science; the Ministry of Health, Welfare and Sport; the
European Commission (DG XII); and the Municipality of Rotterdam. None
of the funders had any role in the design and conduct of the study; the
collection, management, analysis, and interpretation of the data; and in
the preparation, review, or approval of the manuscript. This study is further
supported by the Senior Scientist Grant from the Dutch Heart Foundation
(03-004-2021-T050). Zuolin Lu is a recipient of a scholarship under the
China Scholarship Council (201906940022).